PS Plate

A PS (pre-sensitized) plate is a printing plate used in the offset printing process. It is an offset printing plate that uses a photosensitive coating to transfer ink to the paper. Offset printing is a common method for producing high-quality prints, and PS plates are an important part of the process.

• Usage: Widely used in offset printing industry.
• Composition: Usually made of aluminum, coated with a photosensitive layer.

PS plate is an important part of the offset printing process. PS plate has stable performance, fast sensitivity, large development latitude, and high print durability.

PS Plate Structure Composition

PS plates are made from a variety of materials, including aluminum, paper, and polyester. The photosensitive coating on the plate is usually made from a mixture of polymers, monomers and photoinitiators. When exposed to UV light, the coating hardens and becomes insoluble, creating a template that can transfer ink to paper.

The PS plate is composed of a substrate and a PS plate coating, that is, a photosensitive layer. The substrate is mostly an aluminum-based plate. The photosensitive layer is a layer formed by coating photosensitive liquid on the substrate.

Commonly used PS aluminum plate base materials are generally 1050 and 1060 aluminum plates in H18 state. In addition to being used to produce PS plates, 1060 aluminum plates are also widely used in positive PS plates, thermal CTP plates, photosensitive CTP plates, UV-CTP plates, etc.

Advantages of PS Plate

It has good stability, wide tolerance and high sensitivity, and is suitable for all mainstream printing machines, developing machines and developers.

• High quality: Able to produce clear and detailed images.
• Durability: Withstands long printing periods.
• Consistency: Provides uniform and consistent image reproduction.
• Compatibility: Works with a variety of inks and substrates.
• Environmentally Friendly: PS plates can be recycled or safely disposed of, making them a more sustainable printing option.
• Cost-Effectiveness: PS plates are relatively cheap compared to other types of printing plates.

PS Plate Type

• Positive PS plates: These plates produce an image when exposed, and the exposed areas become insoluble, while the unexposed areas remain soluble. They are great for printing fine lines and small text.

• Negative Working PS Plates: These plates produce an image when exposed to light, with the exposed areas remaining soluble and the unexposed areas becoming insoluble. They are ideal for printing large areas of solid color.

• Thermal PS Plates: These plates use heat instead of light to create the stencil. They are typically used for high-volume printing.

PS Plate Production Process

1. Preparation stage

• PS plate composition: usually made of aluminum and coated with a layer of photosensitive material on the surface.
• PS positive plate: The photosensitive material becomes soluble after exposure and is washed away during development, leaving the graphic part.
• Negative PS printing plate: The unexposed parts are washed away, and the exposed parts form images and text.

2. Exposure

• Process: Use an ultraviolet light source to illuminate the plate through a piece of film with graphics and text.
• Result: Chemical changes occur in the area where the light hits.

3. Develop

• Developer treatment: Dip the exposed PS plate into the developer to remove the parts that have not undergone chemical changes.
• Graphic and text formation: leaving the exposed graphic and text area.

4. Printing

Loading: Install the developed plate on the printing press.

5. Dampening and inking

The non-image and text parts absorb water and form a protective layer.

The graphic and text parts absorb ink but not water.

6. Printing process: The ink is transferred from the plate to the blanket, and then transferred from the blanket to paper and other substrates.

PS Plate Technical Data Sheet

PS Plate Application Areas

PS version is used for high-end commercial color printing and newspaper printing. The unique production process and high-quality raw materials enable the printing plate to have high photosensitivity speed, good halftone dot reproduction and stable performance.

• Commercial printing: magazines, brochures, catalogs.
• Newspaper printing: high-speed production and high-quality imaging.
• Packaging: Labels, boxes and other packaging materials.

Factors affecting the quality of PS Plate

1. Storage conditions

• Temperature: PS plates should be stored in a cool place, the ideal temperature is 15-25℃. Excessively high temperatures will accelerate the aging of the photosensitive coating.
• Humidity: A dry environment is best, and the relative humidity should be controlled at 40-60%. Excessive humidity will cause the coating to become damp and affect the photosensitivity effect.
• Light: Avoid exposure to sunlight or strong light, because ultraviolet rays will activate the photosensitive layer in advance and reduce the service life of the plate.

2. Treatment method

• Handling: Handle it with care during handling, avoid violent collisions and squeezes, and prevent plate deformation or coating peeling.
• Gloves: Clean gloves should be worn during operation to avoid skin oil and dirt contaminating the plate.
• Dustproof: Keep the working environment clean to prevent dust or other impurities from adhering to the plate and affecting the exposure and development effects.

3. Exposure time

• Exposure intensity: Exposure intensity and time must match. Exposure time that is too long or too short will affect the fineness and contrast of the image. The optimal exposure time should usually be determined based on the plate manufacturer's recommendations and actual experiments.
• Exposure uniformity: Ensure that the exposure light source is evenly distributed to avoid local overexposure or underexposure, resulting in uneven images.
• Light source quality: Use a stable exposure light source with suitable spectrum. Ultraviolet light source is commonly used, and keep its power and spectral output stable.

4. Development process

• Developer concentration: The concentration of the developer should be controlled within the specified range. Too high or too low will affect the development effect.
• Development time: Too long or too short a development time will result in partial loss or residue of the image. The development time should be adjusted according to the type and concentration of the developer.
• Developing temperature: The temperature of the developer should be controlled within an appropriate range, usually 20-25°C. Too high or too low a temperature will affect the development effect.

5. Photosensitive coating quality

• Coating uniformity: The photosensitive coating should be uniform to avoid uneven coating thickness, which will affect the exposure and development effects.
• Coating adhesion: The coating should have good adhesion to prevent it from falling off during development or printing.

6. Printing environment and equipment

• Printing pressure: The pressure of the printing press should be appropriate. Too much or too little pressure will affect the image transfer effect and the service life of the plate.
• Fountain solution: The quality and ratio of the fountain solution should be appropriate to maintain a good ink and ink balance and avoid premature aging or contamination of the plate.

PS Plate Storage

• Storage: Store in a cool, dry place away from direct sunlight.
• Handling: Handle with care to avoid scratches or contamination.
• Cleaning: Follow manufacturer's guidelines for cleaning solutions and methods.

PS plates are an important part of the offset printing process, providing cost-effective, high-quality and environmentally friendly printing solutions. PS Edition is known for its quality, durability and versatility. They play a vital role in the efficient production of various printing materials.

The following PS and CTP plate may interest you

• 

  Positive CTCP Plate

• 

  Thermal CTP plate (Single-layer)

• 

  Thermal CTP Plate (Double Layer)

• 

  Thermal CTP Plate(Process-less)

• 

  Positive CTCP Single Layer Plates

• 

  Positive CTCP Plate(Double Layer)

• 

  Positive UV-CTP Plate

• 

  Ctp Plates for Offset Printing

• 

  Presensitized offset plate

• 

  Flexo Ctp Machine

• 

  Ps Plate Offset Printing

• 

  Processless plate

• 

  Positive Thermal CTP Plate